The present invention relates generally to Tee configuration check valves and more particularly to ball-retaining stops in these check valves.
In the past, a Tee check valve would be provided with a boss on the crossbar into which a hole would be drilled and reamed so as to allow the press fitting of a dowel pin therein for projection into the crossbar of the Tee to hold the ball in the side of the crossbar which had the ball valve seat. The disadvantages of this method include: the cost of drilling and reaming the hole in the Tee; the cost of the pin; the external leakage around the pin with high system pressures; the difficulty of removing the pin for maintenance; and the excessive material required in the Tee in order to be able to support the pin.